<i>(Invited)</i> Development of AEM Electrolysis as Part of the DAEMONHYC Project: Some Points of Understanding

As part of the DAEMOHYC project funded by the French government, we are developing alkaline anion exchange membrane electrolysis without platinum group materials, down to the 25cm 2 single cell scale. Our consortium comprises five university laboratories and two industrial partners. Our strategy is to explore different ways of shaping materials, from the simplest, cheapest and most robust to the most performing, expensive and complex. For example, for the anode, we began by considering the use of simple activated stainless steel felts, without the use of ionomer [1]. We then textured these felts and decorated them with cobalt spinels by a combustion method using an amino acid ignition agent. The advantage of this shaping method is the robustness of the resulting electrodes and their good electronic conductivity, compared with electrodes obtained by ink deposition. The disadvantage is their low ionic conductivity, which essentially depends on the KOH concentration within the electrode. We have demonstrated that it is possible to increase the KOH concentration within the electrode thanks to the system architecture (dry cathode operation) and the good management of mass transport (PTL permeability), so as to maintain a pH gradient between the electrode and the feeding channels. Experimental studies combined with modeling work have enabled us to define stability domains for the various materials used, and to deduce optimal system control parameters (temperature, electrolyte pH, pressures, flow rates, clamping stress). In this presentation, we propose to take stock of the various advances made in the DAEMONHYC project in terms of materials, shaping, modeling and testing on the scale of the 25cm 2 single cell. The idea is to share some insights that will help those involved in anion exchange membrane electrolysis to define their R&amp;D strategy. The authors would like to thank the PEPR-H2 (ANR-22-PEHY-0010) for the financing support [1] Magnier, L., Cossard, G., Martin, V. et al. Fe–Ni-based alloys as highly active and low-cost oxygen evolution reaction catalyst in alkaline media. Nat. Mater. 23, 252–261 (2024) Figure 1